java - 如何检查用户使用哪个构造函数

Question

我有这样的构造函数

    public Name(String firstName, String lastName)
{
    setFirstName(firstName);
    setLastName(lastName);        
}

public Name(String firstName, String lastName, String middleName)
{
    setFirstName(firstName);
    setLastName(lastName);
    setMiddleName(middleName);
}

我想像这样重写我的 toString() 方法

    @Override
    public String toString()
    {
        if(no middle name)
        {return  getFirstName() + " " + getLastName();}
        else if(has a middle name)
        {return  getFirstName() + " " + getMiddleName() + " " + getLastName();}
    }

我应该做什么？

Answer 1

@Override
public String toString()
{
    if(middleName == null)
    {return  getFirstName() + " " + getLastName();}
    else
    {return  getFirstName() + " " + getMiddleName() + " " + getLastName();}
}

您可能想查看Guava's Strings对于 isNullOrEmpty()，例如(并且只有一个返回，正如 riccardo.cardin 指出的那样，这是更好的做法):

@Override
public String toString()
{
    String nameString = null;

    if (Strings.isNullOrEmpty(middleName))
    {
        nameString = getFirstName() + " " + getLastName();
    }
    else
    {
        nameString = getFirstName() + " " + getMiddleName() + " " + getLastName();
    }

    return nameString;
}